Phase change inks containing colorant compounds

ABSTRACT

Phase change inks comprising a carrier and a colorant composition including a basic dye component and an acid dye component providing an internal salt composition wherein at least one of the basic dye component, the acid dye component, or both the basic dye component and the acid dye component comprises a waxy moiety.

Cross-reference is made to the following co-pending applications:

Co-pending Application U.S. Ser. No. 11/702,892, filed concurrently herewith, entitled “Colorant Compounds,” with the named inventor Jeffery H. Banning, the disclosure of which is totally incorporated herein by reference, discloses a colorant composition having a basic dye component and an acid dye component providing an internal salt composition wherein at least one of the basic dye component, the acid dye component, or both the basic dye component and the acid dye component comprises a waxy moiety.

Co-pending Application U.S. Ser. No. 11/702,890, filed concurrently herewith, entitled “Colorant Compounds,” with the named inventor Jeffery H. Banning, the disclosure of which is totally incorporated herein by reference, discloses a colorant compound.

Co-pending Application U.S. Ser. No. 11/702,818, filed concurrently herewith, entitled “Phase Change Inks Containing Colorant Compounds,” with the named inventor Jeffery H. Banning, the disclosure of which is totally incorporated herein by reference, discloses a phase change ink composition comprising a phase change ink carrier and a colorant compound.

BACKGROUND

The present disclosure is generally related to phase change inks. More specifically, the present disclosure is directed to hot melt or phase change inks containing specific colorant compounds. One embodiment of the present disclosure is directed to a phase change ink carrier and colorant compositions having a basic dye component and an acid dye component providing an internal salt composition wherein at least one of the basic dye component, the acid dye component, or both the basic dye component and the acid dye component comprises a waxy moiety.

In general, phase change inks (sometimes referred to as “hot melt inks”) are in the solid phase at ambient temperature, but exist in the liquid phase at the elevated operating temperature of an ink jet printing device. At the jet operating temperature, droplets of liquid ink are ejected from the printing device and, when the ink droplets contact the surface of the recording substrate, either directly or via an intermediate heated transfer belt or drum, they quickly solidify to form a predetermined pattern of solidified ink drops. Phase change inks have also been used in other printing technologies, such as gravure printing, as disclosed in, for example, U.S. Pat. No. 5,496,879 and German Patent Publications DE 4205636AL and DE 4205713AL, the disclosures of each of which are totally incorporated herein by reference.

Phase change inks for color printing typically comprise a phase change ink carrier composition which is combined with a phase change ink compatible colorant. In a specific embodiment, a series of colored phase change inks can be formed by combining ink carrier compositions with compatible subtractive primary colorants. The subtractive primary colored phase change inks can comprise four component dyes, namely, cyan, magenta, yellow and black, although the inks are not limited to these four colors. These subtractive primary colored inks can be formed by using a single dye or a mixture of dyes. For example, magenta can be obtained by using a mixture of Solvent Red Dyes or a composite black can be obtained by mixing several dyes. U.S. Pat. Nos. 4,889,560, 4,889,761, and U.S. Pat. No. 5,372,852, the disclosures of each of which are totally incorporated herein by reference, teach that the subtractive primary colorants employed can comprise dyes from the classes of Color Index (C.I.) Solvent Dyes, Disperse Dyes, modified Acid and Direct Dyes, and Basic Dyes. The colorants can also include pigments, as disclosed in, for example, U.S. Pat. No. 5,221,335, the disclosure of which is totally incorporated herein by reference. U.S. Pat. No. 5,621,022, the disclosure of which is totally incorporated herein by reference, discloses the use of a specific class of polymeric dyes in phase change ink compositions.

Phase change inks have also been used for applications such as postal marking, industrial marking, and labeling.

Phase change inks are desirable for ink jet printers because they remain in a solid phase at room temperature during shipping, long term storage, and the like. In addition, the problems associated with nozzle clogging as a result of ink evaporation with liquid ink jet inks are largely eliminated, thereby improving the reliability of the ink jet printing. Further, in phase change ink jet printers wherein the ink droplets are applied directly onto the final recording substrate (for example, paper, transparency material, and the like), the droplets solidify immediately upon contact with the substrate, so that migration of ink along the printing medium is prevented and dot quality is improved.

Compositions suitable for use as phase change ink carrier compositions are known. Some representative examples of references disclosing such materials include U.S. Pat. Nos. 3,653,932, 4,390,369, 4,484,948, 4,684,956, 4,851,045, 4,889,560, 5,006,170, 5,151,120, 5,372,852, 5,496,879, European Patent Publication 0187352, European Patent Publication 0206286, German Patent Publication DE 4205636AL, German Patent Publication DE 4205713AL, and PCT Patent Application WO 94/04619, the disclosures of each of which are totally incorporated herein by reference. Suitable carrier materials can include paraffins, microcrystalline waxes, polyethylene waxes, ester waxes, fatty acids and other waxy materials, fatty amide containing materials, sulfonamide materials, resinous materials made from different natural sources (tall oil rosins and rosin esters, for example), and many synthetic resins, oligomers, polymers, and copolymers.

While known compositions and processes are suitable for their intended purposes, a need remains for new colorant compositions for making composite black and other colors (for example, green). In addition, a need remains for colorant compositions particularly suitable for use in phase change inks. Further, a need remains for black and other colorants with desirable thermal stability. Additionally, a need remains for black and other colorants that exhibit minimal undesirable discoloration when exposed to elevated temperatures. There is also a need for black and other colorants that exhibit a desirable brilliance. In addition, there is a need for black and other colorants that exhibit a desirable hue. Further, there is a need for black and other colorants that are of desirable chroma. Additionally, there is a need for black and other colorants that have desirably high lightfastness characteristics. A need also remains for black and other colorants that have a desirably pleasing color. In addition, a need remains for black and other colorants that exhibit desirable solubility characteristics in phase change ink carrier compositions. Further, a need remains for black and other colorants that enable phase change inks to be jetted at temperatures of over 135° C. while maintaining thermal stability. Further, a need remains for magenta colorants for use in solid ink printers that operate with lower print head temperatures much lower than 135° C. as well as in ultraviolet radiation curable systems. Additionally, a need remains for black and other colorants that enable phase change inks that generate images with low pile height. There is also a need for black and other colorants that enable phase change inks that generate images that approach lithographic thin image quality. In addition, there is a need for black and other colorants that exhibit oxidative stability. Further, there is a need for black and other colorants that do not precipitate from phase change ink carriers. Additionally, there is a need for black and other colorants that do not, when included in phase change inks, diffuse into adjacently printed inks of different colors. A need also remains for black and other colorants that do not leach from media such as phase change ink carriers into tape adhesives, paper, or the like. In addition, a need remains for black and other colorants that, when incorporated into phase change inks, do not lead to clogging of a phase change ink jet printhead. Further, there is a need for black and other colorants that enable phase change inks that generate images with sharp edges that remain sharp over time. Additionally, there is a need for black and other colorants that enable phase change inks that generate images which retain their high image quality in warm climates. Further, there is a need for black and other colorants that enable phase change inks that generate images of desirably high optical, density. Additionally, there is a need for black and other colorants that, because of their good solubility in phase change ink carriers, enable the generation of images of low pile height without the loss of desirably high optical density. A need also remains for black and other colorants that enable cost-effective inks.

The appropriate components and process aspects of the each of the foregoing may be selected for the present disclosure in embodiments thereof.

SUMMARY

The present disclosure is directed to a phase change ink composition comprising a phase change ink carrier and a colorant composition having a basic dye component and an acid dye component providing an internal salt composition wherein at least one of the basic dye component, the acid dye component, or both the basic dye component and the acid dye component comprises a waxy moiety.

The present disclosure is further directed to a phase change ink composition comprising a phase change ink carrier and a colorant composition having a basic dye component and an acid dye component providing an internal salt composition wherein at least one of the basic dye component or the acid dye component comprises a waxy moiety, wherein the basic dye component comprises a compound of the formula

wherein R₁, R₂, R₃, and R₄, each, independently of the others, is (i) a hydrogen atom, (ii) an alkyl group, (iii) an aryl group, (iv) an arylalkyl group, or (v) an alkylaryl group, wherein R₅, R₆, R₇, and R₈, each, independently of the others, is (i) a hydrogen atom, (ii) an alkyl group, (iii) an aryl group, (iv) an arylalkyl group, or (v) an alkylaryl group, wherein R₁ and R₂ can be joined together to form a ring, wherein R₃ and R₄ can be joined together to form a ring, wherein R₅ and R₆ can be joined together to form a ring, and wherein R₁, R₂, R₃, R₄, R₅ and R₆ can each be joined to a phenyl ring in the central structure, wherein R₁ and R₂ can each optionally be joined to one or both of R₆ and R₇ to form a ring, wherein R₃ and R₄ can each optionally be joined to one or both of R₅ and R₈ to form a ring; wherein R₉, R₁₀, and R₁₁, are each independently of the others optionally included and wherein if included each of R₉, R₁₀, and R₁₁, independently of the others, is (i) a hydroxy group, (ii) a halogen atom, (iii) an amine group, (iv) an imine group, (v) an ammonium group, (vi) a cyano group, (vii) a pyridine group, (viii) a pyridinium group, (ix) an ether group, (x) an aldehyde group, (xi) a ketone group, (xii) an ester group, (xiii) an amide group, (xiv) a carbonyl group, (xv) a thiocarbonyl group, (xvi) a sulfoxide group, (xvii) a nitrile group, (xviii) a mercapto group, (xix) a nitro group, (xx) a nitroso group, (xxi) a sulfone group, (xxii) an acyl group, (xxiii) an acid anhydride group, (xxiv) an azide group, (xxv) an azo group, (xxvi) a cyanato group, (xxvii) an isocyanato group, (xxviii) a thiocyanato group, (xxix) an isothiocyanato group, (xxx) a urethane group, (xxxi) a urea group, or a mixture or combination thereof, and the like, wherein two or more substituents can be joined together to form a ring, wherein R₉, R₁₀, and R₁₁ can each be joined to a phenyl ring in the central structure;

and wherein the acid dye component includes an anion providing a counter ion to the basic dye component providing a basic dye-acid dye internal salt composition.

In embodiments, at least one of the basic dye component or the acid dye component comprises a waxy moiety or both the basic dye component and the acid dye component comprise a waxy moiety. As used herein, the term waxy moiety means having sufficient carbon atoms in the alkyl portion to be soluble in hot melt or phase change ink vehicles (hot melt ink vehicles typically comprising a wax). For example, in embodiments, a waxy moiety herein is alkyl group having from about 4 to about 150 carbon atoms. For example, in embodiments, a waxy moiety herein is an alkyl group having about 4, 5, 6, 7, 8, 9, 10, 12, 16, or 18 carbon atoms, or about 30 to about 150 carbon atoms, an alkylaryl group having about 4, 5, 6, 7, 8, 9, 10, 12, 16, or 18 carbon atoms, or about 30 to about 150 carbon atoms, or an arylalkyl group having about 4, 5, 6, 7, 8, 9, 10, 12, 16, or 18 carbon atoms, or about 30 to about 150 carbon atoms. In embodiments, a waxy moiety herein is an aryl group having from about 6 to about 20 carbon atoms or from about 6 to about 12 carbon atoms. In embodiments, the ratio of alkyl carbon atoms to aryl carbon atoms in the waxy moiety is from about 10 to about 1 or from about 2 to about 1.

DETAILED DESCRIPTION

The present disclosure is directed to a phase change ink comprising a colorant composition having a basic dye component and an acid dye component providing an internal salt composition wherein at least one of the basic dye component, the acid dye component, or both the basic dye component and the acid dye component comprises a waxy moiety. As used herein, the term waxy moiety means having sufficient carbon atoms in the alkyl portion to be soluble in hot melt or phase change ink vehicles (such vehicles typically comprising a wax). For example, in embodiments, a waxy moiety herein is an alkyl group having from about 4 to about 150 carbon atoms. For example, in embodiments, a waxy moiety herein is an alkyl group having about 4, 5, 6, 7, 8, 9, 10, 12, 16, or 18 carbon atoms, or about 30 to about 150 carbon atoms, an alkylaryl group having about 4, 5, 6, 7, 8, 9, 10, 12, 16, or 18 carbon atoms, or about 30 to about 150 carbon atoms, or an arylalkyl group having about 4, 5, 6, 7, 8, 9, 10, 12, 16, or 18 carbon atoms, or about 30 to about 150 carbon atoms. In embodiments, a waxy moiety herein is an aryl moiety having from about 6 to about 20 carbon atoms or from about 6 to about 12 carbon atoms. In embodiments, the ratio of alkyl carbon atoms to aryl carbon atoms in the waxy moiety is from about 10 to about 1 or from about 2 to about 1.

Basic dyes suitable for compositions can be selected from any basic dye listed in the Color Index, including for example, but not limited to, analogs of Basic Green 1, 4, and 5; Basic orange 2, 14, 21; Basic Red 1, 2, 5, 9, and 29; Basic Violet 1, 2, 3, 4, 10; Basic yellow 1 and 2, mixtures and combinations thereof, and the like, among others, wherein at least one of the basic dye component, the acid dye component, or both the basic dye component and the acid dye component comprises a waxy moiety.

Acid dyes suitable for compositions can be selected from any acid dye listed in the Color Index, including for example, but not limited to, Acid Black 1, 2, 24, 26, 29, 50, 52, 58, 58:1, 60, 63, 63:1, 65, 76, 77, 92, 94, 107, 127, 131, 131:1, 132, 132:1, 139, 164, 170, 170:1172, 187, 188, 189, 194, 214, 215, 218, 222, and 224; Acid Blue 1, 7, 9, 15, 22, 25, 27, 29, 40, 41, 45, 61:1, 62, 72, 74, 80, 83, 90, 92, 93, 104, 113, 118, 120, 127, 127:1, 129, 140, 145, 147, 158, 170, 171, 172, 182, 185, 193, 204, 205, 209, 221, 225, 229, 232, 239, 247, 258, 260, 264, 277, 278, 279, 280, 284, 288, 290, 296, 298, 312, 317, 321, 324, 330, 335, and 455; Acid Brown 14, 19, 28, 44:1, 45, 45:1, 50, 58, 96, 97, 98, 103, 106, 107, 108, 110, 112, 113, 114, 116, 126, 127, 147, 160, 161, 163m, 165, 188, 189, 191, 216, 226, 227, 235, 237, 239, 248, 282, 283, 289, 298, 304, 311, 330, 341, 342, 343, 345, 348, 349, 355, 357, 358, 359, 360, 362, 384, 396, and 397; Acid Green 1, 3, 5, 9, 12, 16, 20, 25, 27, 28, 35, 40, 41, 70, 104, 108, 112, 113, and 116; Acid Orange 1, 3, 6, 7, 8, 10, 12, 24, 33, 47, 51, 52, 60, 61, 62, 63, 64, 67, 69, 74, 80, 86, 116, 120, 127, 135, 142, 144, 154, 156, 161, 162, and 168; Acid Red 1, 2, 4, 8, 14, 17, 18, 26, 27, 29, 33, 37, 42, 44, 50, 51, 52, 57, 64, 66, 73, 80, 85, 87, 88, 89, 90, 91, 92, 94, 97, 99, 103, 111, 114, 115, 118, 119, 127, 128, 131, 137, 138, 143, 145, 150, 151, 167, 174, 182, 183, 186, 194, 211, 213, 217, 226, 249, 251, 252, 257, 259, 260 263, 264, 266, 274, 289, 299, 310, 308, 315, 316, 336, 337, 359, 360, 361, 362, 364, 384, 395, 396, 399, 404, 410, 414, 415, 426, 439, and 735; Acid Violet 1, 3, 7, 9, 11, 12, 17, 19, 34, 43, 47, 48, 49, 54, 66, 76, 90, 102, 102:1, 109, 121, and 126; Acid Yellow 1, 3, 5, 7, 9, 11, 17, 19, 23, 25, 29, 34, 36, 40, 42, 44, 49, 54, 61, 65, 67, 73, 76, 79, 99, 104, 114, 116, 121, 127, 128, 129, 135, 137, 151, 152, 158:1, 159, 159:1, 169, 174, 184, 198, 199, 200, 204, 218, 219, 219:1220, 221, 230, 232, 235, 239, and 241 and 99, mixtures and combinations thereof, and the like, among others, wherein at least one of the basic dye component, the acid dye component, or both the basic dye component and the acid dye component comprises a waxy moiety.

The present disclosure is directed in embodiments to phase change inks comprising colorant compositions having a basic dye component and an acid dye component providing an internal salt composition wherein at least one of the basic dye component or the acid dye component comprises a waxy moiety, or wherein both the basic dye component and the acid dye component comprises a waxy moiety, wherein the basic dye component comprises a compound of the formula

wherein R₁, R₂, R₃, R₄, R₅, R₆, R₇, and R₈ each, independently of the others, is (i) a hydrogen atom, (ii) an alkyl group (including linear, branched, saturated, unsaturated, cyclic, substituted, and unsubstituted alkyl groups, and wherein hetero atoms, such as oxygen, nitrogen, sulfur, silicon, boron, phosphorus, and the like either may or may not be present in the alkyl group), in one embodiment with at least about 1 carbon atom, in another embodiment with at least about 2 carbon atoms, in yet another embodiment with at least about 6 carbon atoms, in another embodiment with at least about 8 carbon atoms, and in yet another embodiment with at least about 18 carbon atoms, and in one embodiment with no more than about 55 carbon atoms, in another embodiment with no more than about 30 carbon atoms, and in yet another embodiment with no more than about 20 carbon atoms, although the number of carbon atoms can be outside of these ranges, (iii) an aryl group (including unsubstituted and substituted aryl groups, and wherein hetero atoms, such as oxygen, nitrogen, sulfur, silicon, phosphorus, and the like either may or may not be present in the aryl group), in one embodiment with at least about 6 carbon atoms, in another embodiment with at least about 10 carbon atoms, and in yet another embodiment with at least about 14 carbon atoms, and in one embodiment with no more than about 26 carbon atoms, in another embodiment with no more than about 22 carbon atoms, and in yet another embodiment with no more than about 18 carbon atoms, although the number of carbon atoms can be outside of these ranges, (iv) an arylalkyl group, (including unsubstituted and substituted arylalkyl groups, wherein the alkyl portion of the arylalkyl group can be linear, branched, saturated, unsaturated, and/or cyclic, and wherein hetero atoms, such as oxygen, nitrogen, sulfur, silicon, phosphorus, and the like either may or may not be present in either or both of the alkyl portion and the aryl portion of the arylalkyl group), in one embodiment with at least about 7 carbon atoms, in another embodiment with at least about 12 carbon atoms, and in yet another embodiment with at least about 18 carbon atoms, and in one embodiment with no more than about 55 carbon atoms, in another embodiment with no more than about 30 carbon atoms, and in yet another embodiment with no more than about 20 carbon atoms, although the number of carbon atoms can be outside of these ranges, such as benzyl or the like or (v) an alkylaryl group, (including unsubstituted and substituted alkylaryl groups, wherein the alkyl portion of the alkylaryl group can be linear, branched, saturated, unsaturated, and/or cyclic, and wherein hetero atoms, such as oxygen, nitrogen, sulfur, silicon, phosphorus, and the like either may or may not be present in either or both of the alkyl portion and the aryl portion of the alkylaryl group), in one embodiment with at least about 7 carbon atoms, in another embodiment with at least about 12 carbon atoms, and in yet another embodiment with at least about 18 carbon atoms, and in one embodiment with no more than about 55 carbon atoms, in another embodiment with no more than about 30 carbon atoms, and in yet another embodiment with no more than about 20 carbon atoms, although the number of carbon atoms can be outside of these ranges, such as tolyl or the like wherein R₁ and R₂ can be joined together to form a ring, wherein R₃ and R₄ can be joined together to form a ring, wherein R₅ and R₆ can be joined together to form a ring, and wherein R₁, R₂, R₃, R₄, R₅ and R₆ can each be joined to a phenyl ring in the central structure; wherein R₁ and R₂ can each optionally be joined to one or both of R₆ and R₇ to form a ring, wherein R₃ and R₄ can each optionally be joined to one or both of R₅ and R₈ to form a ring;

wherein each of R₉, R₁₀, and R₁₁, independently of the others, is optionally included and wherein if included each of each of R₉, R₁₀, and R₁₁, independently of the others, is (i) an alkyl group (including linear, branched, saturated, unsaturated, cyclic, substituted, and unsubstituted alkyl groups, and wherein hetero atoms, such as oxygen, nitrogen, sulfur, silicon, phosphorus, and the like either may or may not be present in the alkyl group), in one embodiment with at least about 1 carbon atom, and in one embodiment with no more than about 50 carbon atoms, in another embodiment with no more than about 30 carbon atoms, and in yet another embodiment with no more than about 18 carbon atoms, although the number of carbon atoms can be outside of these ranges, (ii) an aryl group (including unsubstituted and substituted aryl groups, and wherein hetero atoms, such as oxygen, nitrogen, sulfur, silicon, phosphorus, and the like either may or may not be present in the aryl group), in one embodiment with at least about 6 carbon atoms, and in one embodiment with no more than about 55 carbon atoms, in another embodiment with no more than about 30 carbon atoms, and in yet another embodiment with no more than about 18 carbon atoms, although the number of carbon atoms can be outside of these ranges, (iii) an arylalkyl group (including unsubstituted and substituted arylalkyl groups, wherein the alkyl portion of the arylalkyl group can be linear, branched, saturated, unsaturated, and/or cyclic, and wherein hetero atoms, such as oxygen, nitrogen, sulfur, silicon, phosphorus, and the like either may or may not be present in either or both of the alkyl portion and the aryl portion of the arylalkyl group), in one embodiment with at least about 7 carbon atoms, and in one embodiment with no more than about 55 carbon atoms, in another embodiment with no more than about 30 carbon atoms, and in yet another embodiment with no more than about 18 carbon atoms, although the number of carbon atoms can be outside of these ranges, such as benzyl or the like, (iv) an alkylaryl group (including unsubstituted and substituted alkylaryl groups, wherein the alkyl portion of the alkylaryl group can be linear, branched, saturated, unsaturated, and/or cyclic, and wherein hetero atoms, such as oxygen, nitrogen, sulfur, silicon, phosphorus, and the like either may or may not be present in either or both of the alkyl portion and the aryl portion of the alkylaryl group), in one embodiment with at least about 7 carbon atoms, and in one embodiment with no more than about 55 carbon atoms, in another embodiment with no more than about 30 carbon atoms, and in yet another embodiment with no more than about 18 carbon atoms, although the number of carbon atoms can be outside of these ranges, such as tolyl or the like, (v) a halogen atom, such as fluorine, chlorine, bromine, iodine, or the like, (vi) an ester group, (vii) an amide group, (viii) a sulfone group, (ix) an amine group or ammonium group, (x) a nitrile group, (xi) a nitro group, (xii) a hydroxy group, (xiii) a cyano group, (xiv) a pyridine or pyridinium group, (xv) an ether group, (xvi) an aldehyde group, (xvii) a ketone group, (xviii) a carbonyl group, (xix) a thiocarbonyl group, (xx) a sulfide group, (xxi) a sulfoxide group, (xxii) a mercapto group, (xxiii) a nitroso group, (xxiv) an acyl group, (xxv) an acid anhydride group, (xxvi) an azide group, (xxvii) an azo group, (xxviii) a cyanato group, (xxix) an isocyanato group, (xxx) a thiocyanato group, (xxxi) an isothiocyanato group, (xxxii) a urethane group, or (xxxiii) a urea group, wherein R₉, R₁₀ and R₁₁ can each be joined to a phenyl ring in the central structure;

wherein a, b and c each, independently of the others, is an integer which is0, 1, 2, or 3;

and wherein the acid dye component includes an anion providing a counter ion to the basic dye component providing a basic dye-acid dye internal salt composition (that is, the anion is the acid dye counter ion).

Colorants of the present disclosure can be prepared by any desired or effective procedure.

Any desired basic dye can be selected for embodiments herein. For example, basic dyes can include any basic dye listed in the Color Index, including but not limited to, for example, analogs of Basic Green 1, 4, and 5; Basic Orange 2, 14, 21; Basic Red 1, 2, 5, 9, and 29; Basic Violet 1, 2, 3, 4, 10; and Basic Yellow 1 and 2, among others.

Further any desired acid dye can be selected for embodiments herein. For example, acid dyes can include any acid dye listed in the Color Index, including but not limited to Acid Black 1, 2, 24, and 48; Acid Blue 1, 7, 9, 25, 29, 40, 45, 74, 80, 83, 90, 92, 113, 120, 129, 147; Acid Green 1, 3, 5, 25, 27, and 50; Acid Orange 6, 7, 8, 10, 12, 51, 52, 63, and 74; Acid Red 1, 4, 8, 14, 17, 18, 26, 27, 29, 37, 44, 50, 51, 52, 66, 73, 87, 88, 91, 92, 94, 97, 103, 114, 150, 151, and 183; Acid Violet 79, 17, and 19; Acid Yellow 1, 3, 9, 11, 17, 23, 25, 29, 34, 36, 42, 54, 73, 76, and 99, among others.

See, for example, Color Index International, a reference database jointly maintained by the Society of Dyers and Colourists and the American Association of Textile Chemists and Colorists, available online at http://www.colour-index.org/.

Colorant compounds for inks of the present disclosure can be prepared by any desired or effective procedure.

In embodiments, synthesis can comprise, for example, synthesis of a Leuco version of a basic dye component via a condensation step, oxidation of the Leuco version of the basic dye, formation of the carbinol form of the basic dye, formation of an acid containing dye component, for example a carboxylic acid containing methine dye, and formation of a basic dye-acid dye internal salt composition.

Synthesis of Leuco Version of Basic Dye Component

For example, the Leuco version of the basic dye component can be synthesized by condensation reaction of an aldehyde with an aniline having the desired pendant groups selected as defined for the colorant herein, heated, either neat or, optionally, in the presence of a solvent, after which an acid is added, for example concentrated H₂SO₄ with additional heating.

The aldehyde component and the aniline component are present in any desired or effective relative amounts, in one embodiment at least about 1 mole of aldehyde component per every 2 moles of aniline component, in another embodiment at least about 0.5 mole of aldehyde component per every 2 moles of aniline component, and in yet another embodiment at least about 0.9 mole of aldehyde component per every 2 moles of aniline component, and in one embodiment no more than about 1.9 moles of aldehyde component per every 2 moles of aniline component, in another embodiment no more than about 1.5 moles of aldehyde component per every 2 moles of aniline component, and in yet another embodiment no more than about 1.1 moles of aldehyde component per every 2 moles of aniline component, although the relative amounts can be outside of these ranges.

If desired, the reaction can be run neat, in the absence of a solvent. In addition, if desired, the reaction can be run in the presence of an optional solvent. Examples of suitable solvents include tetramethylene sulfone (sulfolane), N-methyl pyrrolidone, dimethyl formamide, dimethyl sulfoxide, octanol, or the like, as well as mixtures thereof. When present, the optional solvent is present in any desired or effective amount, in one embodiment at least about 1 liter per every 0.1 mole of aldehyde component, in another embodiment at least about 1 liter per every 0.3 mole of aldehyde component, and in yet another embodiment at least about 1 liter per every 0.35 mole of aldehyde component, and in one embodiment no more than about 1 liter per every 2 moles of aldehyde component, in another embodiment no more than about 1 liter per every 1.5 moles of aldehyde component, and in yet another embodiment no more than about 1 liter per every 1 mole of aldehyde component, although the relative amounts can be outside of these ranges.

The mixture of aldehyde component, aniline component, and optional solvent is then heated to any effective temperature, in one embodiment at least about 62° C., in another embodiment at least about 100° C., in another embodiment at least about 150° C., and in yet another embodiment at least about 190° C., and in one embodiment no more than about 280° C., in another embodiment no more than about 220° C., and in yet another embodiment no more than about 200° C., although the temperature can be outside of these ranges.

The mixture of aldehyde component, aniline component, and optional solvent is heated for any effective period of time, in one embodiment at least about 5 minutes, in another embodiment at least about 2 hours, and in yet another embodiment at least about 3 hours, in yet another embodiment at least about 24 hours, and in one embodiment no more than about 4 days, in another embodiment no more than about 60 hours, and in yet another embodiment no more than about 40 hours, although the time can be outside of these ranges.

The product is then neutralized, for example with a NaOH solution, and collected, for example via vacuum filtration. The crude product can then, if desired, be purified, for example by washing with water.

Oxidation of the Leuco Version of the Basic Dye Component

The Leuco version of the basic dye component can then be oxidized for example by combining the Leuco version of the basic dye component with a suitable oxidizing agent heated, either neat or, optionally, in the presence of a solvent, for a period of time and at a temperature sufficient to assure complete oxidation of the Leuco form of the dye to the fully developed form.

Any suitable oxidizing agent can be selected in embodiments herein. For example, the oxidizing agent can be selected from the group consisting of, but not limited to, chloranil, benzoquinone, DDQ (2,3-dichloro-5,6-dicyano-1,4-benzoquinone), as well as other chlorinated quinines, MnO2, PbO₂/HCl, and mixtures and combinations thereof. See, for example, U.S. Pat. No. 5,013,857, which is hereby incorporated by reference herein in its entirety, which is not meant to limit the present disclosure or claims, entitled “Process for the preparation of sulpho-free triphenyl-methane dyestuffs.”

The oxidizing agent can be selected in any suitable amount, for example, in embodiments, about 1 mole of oxidizing agent per every 0.9 moles of Leuco version of the basic dye component, in another embodiment about 1 mole of oxidizing agent component per every 0.95 moles of Leuco version of the basic dye component, in another embodiment about 1 mole of oxidizing agent per every 1 mole of Leuco version of the basic dye component, and in yet another embodiment about 5 mole of oxidizing agent per every 1 mole of Leuco version of the basic dye component, and in one embodiment no more than about 2 moles of oxidizing agent per every 1 mole of Leuco version of the basic dye component, in another embodiment no more than about 1.75 moles of oxidizing agent per every 1 mole of Leuco version of the basic dye component, and in yet another embodiment no more than about 1.5 moles of oxidizing agent per every 1 mole of Leuco version of the basic dye component, although the relative amounts can be outside of these ranges.

If desired, the reaction can be run neat, in the absence of a solvent. In addition, if desired, the reaction can be run in the presence of an optional solvent. Examples of suitable solvents include, but are not limited to, water, methanol, isopropanol, ethyl alcohol, tetramethylene sulfone (sulfolane), N-methyl pyrrolidone, dimethyl formamide, dimethyl sulfoxide, octanol or the like, as well as mixtures thereof. When present, the optional solvent is present in any desired or effective amount, in one embodiment about 1 liter of solvent per every 0.1 mole of Leuco version of the basic dye component, in another embodiment about 1 liter of solvent per every 0.3 mole of Leuco version of the basic dye component, and in yet another embodiment about 1 liter of solvent per every 0.35 mole of Leuco version of the basic dye component, and in one embodiment no more than about 1 liter of solvent per every 2 moles of Leuco version of the basic dye component, in another embodiment no more than about 1 liter of solvent per every 1.5 moles of Leuco version of the basic dye component, and in yet another embodiment no more than about 1 liter of solvent per every 1 mole of Leuco version of the basic dye component, although the relative amounts can be outside of these ranges.

Formation of the Carbinol form of the Basic Dye

After fully oxidizing the basic dye component, the carbinol form of the basic dye can be prepared, for example, by combining the oxidized form of the basic dye and a hydroxide containing base with heating and stirring as suitable to achieve the carbinol form of the basic dye.

Any suitable hydroxide containing base can be selected in embodiments herein. For example, the hydroxide containing base can be selected from the group consisting of, but not limited to, metal hydroxides for example potassium hydroxide, lithium hydroxide, sodium hydroxide, calcium hydroxide, magnesium hydroxide, and barium hydroxide, and mixtures and combinations thereof.

The oxidized form of the basic dye component and the hydroxide containing base are present in any desired or effective relative amounts, in one embodiment about 1 mole of the oxidized form of the basic dye per every about 1 mole of the hydroxide containing base, in another embodiment, about 0.5 mole of the oxidized form of the basic dye per every about 1 mole of the hydroxide containing base, in another embodiment, about 0.75 mole of the oxidized form of the basic dye per every about 1 mole of the hydroxide containing base, although the relative amounts can be outside of these ranges.

The mixture of oxidized form of the basic dye and hydroxide containing base is heated for any effective period of time, in one embodiment at least about 5 minutes, in another embodiment at least about 2 hours, and in yet another embodiment at least about 3 hours, in yet another embodiment at least about 24 hours, and in one embodiment no more than about 4 days, in another embodiment no more than about 60 hours, and in yet another embodiment no more than about 40 hours, although the time can be outside of these ranges.

The product is then neutralized, for example with a NaOH solution, and collected, for example via vacuum filtration. The crude product can then, if desired, be purified, for example by washing with water.

Formation of an Acid Containing Dye

An acid containing dye is prepared by any suitable means, for example, a carboxylic acid containing methane yellow dye is prepared for example by combining an ethoxylated p-formyl aniline (see U.S. Pat. No. 4,658,064, which is hereby incorporated by reference herein in its entirety, which is not meant to limit the present disclosure or claims), cyanoacetic acid, a catalyst, for example ammonium acetate, in a solvent, for example ethanol, with refluxing for a suitable period of time, for example about 4 hours. The solvent is then removed leaving the liquid methane dye.

Formation of the Basic Dye-Acid Dye Internal Salt Composition

The carbinol form of the basic dye and the acid containing dye are combined in any desired or effective relative amounts, in one embodiment about equimolar amounts of each dye although the relative amounts can be outside of this range, with solvent, and heated with stirring, until all of the solvent boiled off.

Examples of suitable solvents include, but are not limited to, ethanol, water, methanol, isopropanol, butanol tetramethylene sulfone (sulfolane), N-methyl pyrrolidone, dimethyl formamide, dimethyl sulfoxide, octanol, or the like, as well as mixtures thereof. When present, the solvent is present in any desired or effective amount, and additional solvent added as necessary to remove the water from the final product. For example, in one embodiment, the solvent can be present in an amount of about 99 grams of solvent per about 1 gram of reactants/product, in yet another embodiment about 75 grams of solvent per about 25 grams of reactants/product, and in yet another embodiment about 25 grams of solvent per about 75 grams of reactants/product, although the relative amounts can be outside of these ranges.

The mixture of carbinol form of the basic dye, acid containing dye, and solvent is heated to any effective temperature, in one embodiment at least about 62° C., in another embodiment at least about 100° C., in another embodiment at least about 150° C., and in yet another embodiment at least about 190° C., and in one embodiment no more than about 280° C., in another embodiment no more than about 220° C., and in yet another embodiment no more than about 200° C., although the temperature can be outside of these ranges. Additional solvent is added and the heating process repeated as necessary to insure removal of the water formed by the carbinol-acid interaction.

Phase change inks of the present disclosure contain a phase change carrier system or composition. The phase change carrier composition is typically designed for use in either a direct printing mode or an indirect or offset printing transfer system.

In the direct printing mode, the phase change carrier composition in one embodiment contains one or more materials that enable the phase change ink (1) to be applied in a thin film of uniform thickness on the final recording substrate (such as paper, transparency material, and the like) when cooled to ambient temperature after printing directly to the recording substrate, (2) to be ductile while retaining sufficient flexibility so that the applied image on the substrate will not fracture upon bending, and (3) to possess a high degree of lightness, chroma, transparency, and thermal stability.

In an offset printing transfer or indirect printing mode, the phase change carrier composition in one embodiment exhibits not only the characteristics desirable for direct printing mode inks, but also certain fluidic and mechanical properties desirable for use in such a system, as described in, for example, U.S. Pat. No. 5,389,958 the disclosure of which is totally incorporated herein by reference.

Any desired or effective carrier composition can be used. Examples of suitable ink carrier materials include fatty amides, such as monoamides, tetra-amides, mixtures thereof, and the like. Specific examples of suitable fatty amide ink carrier materials include stearyl stearamide, a dimer acid based tetra-amide that is the reaction product of dimer acid, ethylene diamine, and stearic acid, a dimer acid based tetra-amide that is the reaction product of dimer acid, ethylene diamine, and a carboxylic acid having at least about 36 carbon atoms, and the like, as well as mixtures thereof. When the fatty amide ink carrier is a dimer acid based tetra-amide that is the reaction product of dimer acid, ethylene diamine, and a carboxylic acid having at least about 36 carbon atoms, the carboxylic acid is of the general formula

wherein R is an alkyl group, including linear, branched, saturated, unsaturated, and cyclic alkyl groups, said alkyl group in one embodiment having at least about 36 carbon atoms, in another embodiment having at least about 40 carbon atoms, said alkyl group in one embodiment having no more than about 200 carbon atoms, in another embodiment having no more than about 150 carbon atoms, and in yet another embodiment having no more than about 100 carbon atoms, although the number of carbon atoms can be outside of these ranges. Carboxylic acids of this formula are commercially available from, for example, Baker Petrolite, Tulsa, Okla., and can also be prepared as described in Example 1 of U.S. Pat. No. 6,174,937, the disclosure of which is totally incorporated herein by reference. Further information on fatty amide carrier materials is disclosed in, for example, U.S. Pat. Nos. 4,889,560, 4,889,761, 5,194,638, 4,830,671, 6,174,937, 5,372,852, 5,597,856, 6,174,937, and British Patent GB 2 238 792, the disclosures of each of which are totally incorporated herein by reference.

Also suitable as phase change ink carrier materials are isocyanate-derived resins and waxes, such as urethane isocyanate-derived materials, urea isocyanate-derived materials, urethane/urea isocyanate-derived materials, mixtures thereof, and the like. Further information on isocyanate-derived carrier materials is disclosed in, for example, U.S. Pat. Nos. 5,750,604, 5,780,528, 5,782,966, 5,783,658, 5,827,918, 5,830,942, 5,919,839, 6,255,432, 6,309,453, British Patent GB 2 294 939, British Patent GB 2 305 928, British Patent GB 2 305 670, British Patent GB 2 290 793, PCT Publication WO 94/14902, PCT Publication WO 97/12003, PCT Publication WO 97/13816, PCT Publication WO 96/14364, PCT Publication WO 97/33943, and PCT Publication WO 95/04760, the disclosures of each of which are totally incorporated herein by reference.

Mixtures of fatty amide materials and isocyanate-derived materials can also be employed as the ink carrier composition for inks of the present disclosure.

Additional suitable phase change ink carrier materials for the present disclosure include paraffins, microcrystalline waxes, polyethylene waxes, ester waxes, amide waxes, fatty acids, fatty alcohols, fatty amides and other waxy materials, sulfonamide materials, resinous materials made from different natural sources (such as, for example, tall oil rosins and rosin esters), and many synthetic resins, oligomers, polymers and copolymers, such as ethylene/vinyl acetate copolymers, ethylene/acrylic acid copolymers, ethylene/vinyl acetate/acrylic acid copolymers, copolymers of acrylic acid with polyamides, and the like, ionomers, and the like, as well as mixtures thereof. One or more of these materials can also be employed in a mixture with a fatty amide material and/or an isocyanate-derived material.

In one specific embodiment, the phase change ink carrier comprises (a) a polyethylene wax, present in the ink in an amount in one embodiment of at least about 25 percent by weight of the ink, in another embodiment of at least about 30 percent by weight of the ink, and in yet another embodiment of at least about 37 percent by weight of the ink, and in one embodiment of no more than about 60 percent by weight of the ink, in another embodiment of no more than about 53 percent by weight of the ink, and in yet another embodiment of no more than about 48 percent by weight of the ink, although the amount can be outside of these ranges; (b) a stearyl stearamide wax, present in the ink in an amount in one embodiment of at least about 8 percent by weight of the ink, in another embodiment of at least about 10 percent by weight of the ink, and in yet another embodiment of at least about 12 percent by weight of the ink, and in one embodiment of no more than about 32 percent by weight of the ink, in another embodiment of no more than about 28 percent by weight of the ink, and in yet another embodiment of no more than about 25 percent by weight of the ink, although the amount can be outside of these ranges; (c) a dimer acid based tetra-amide that is the reaction product of dimer acid, ethylene diamine, and a long chain hydrocarbon having greater than thirty six carbon atoms and having a terminal carboxylic acid group, present in the ink in an amount in one embodiment of at least about 10 percent by weight of the ink, in another embodiment of at least about 13 percent by weight of the ink, and in yet another embodiment of at least about 16 percent by weight of the ink, and in one embodiment of no more than about 32 percent by weight of the ink, in another embodiment of no more than about 27 percent by weight of the ink, and in yet another embodiment of no more than about 22 percent by weight of the ink, although the amount can be outside of these ranges; (d) a urethane resin derived from the reaction of two equivalents of hydroabietyl alcohol and one equivalent of isophorone diisocyanate, present in the ink in an amount in one embodiment of at least about 6 percent by weight of the ink, in another embodiment of at least about 8 percent by weight of the ink, and in yet another embodiment of at least about 10 percent by weight of the ink, and in one embodiment of no more than about 16 percent by weight of the ink, in another embodiment of no more than about 14 percent by weight of the ink, and in yet another embodiment of no more than about 12 percent by weight of the ink, although the amount can be outside of these ranges; (e) a urethane resin that is the adduct of three equivalents of stearyl isocyanate and a glycerol-based propoxylate alcohol, present in the ink in an amount in one embodiment of at least about 2 percent by weight of the ink, in another embodiment of at least about 3 percent by weight of the ink, and in yet another embodiment of at least about 4.5 percent by weight of the ink, and in one embodiment of no more than about 13 percent by weight of the ink, in another embodiment of no more than about 10 percent by weight of the ink, and in yet another embodiment of no more than about 7.5 percent by weight of the ink, although the amount can be outside of these ranges; and (f) an antioxidant, present in the ink in an amount in one embodiment of at least about 0.01 percent by weight of the ink, in another embodiment of at least about 0.05 percent by weight of the ink, and in yet another embodiment of at least about 0.1 percent by weight of the ink, and in one embodiment of no more than about 1 percent by weight of the ink, in another embodiment of no more than about 0.5 percent by weight of the ink, and in yet another embodiment of no more than about 0.3 percent by weight of the ink, although the amount can be outside of these ranges.

The ink carrier is present in the phase change ink of the present disclosure in any desired or effective amount, in one embodiment of at least about 0.1 percent by weight of the ink, in another embodiment of at least about 50 percent by weight of the ink, and in yet another embodiment of at least about 90 percent by weight of the ink, and in one embodiment of no more than about 99 percent by weight of the ink, in another embodiment of no more than about 98 percent by weight of the ink, and in yet another embodiment of no more than about 95 percent by weight of the ink, although the amount can be outside of these ranges.

The phase change inks of the present disclosure contain a colorant composition having a basic dye component and an acid dye component providing an internal salt composition wherein at least one of the basic dye component, the acid dye component, or both the basic dye component and the acid dye component comprises a waxy moiety.

This colorant composition is present in the ink in any desired or effective amount to obtain the desired color or hue, in one embodiment, in an amount of at least about 0.1 percent by weight of the ink, in another embodiment of at least about 0.5 percent by weight of the ink, in yet another embodiment of at least about 1 percent by weight of the ink, in still another embodiment of at least about 2 percent by weight of the ink, and in another embodiment of at least about 3 percent by weight of the ink, and in one embodiment of no more than about 20 percent by weight of the ink, in another embodiment of no more than about 13 percent by weight of the ink, and in yet another embodiment of no more than about 6 percent by weight of the ink, although the amount can be outside of these ranges. The colorant according to the present disclosure can either be the sole colorant in the ink or can be present in combination with other colorants, such as dyes, pigments, mixtures thereof, and the like.

In specific embodiments, the inks of the present disclosure further contain an acid having a Ka value greater than that of the Ka of the carboxylic acid and/or sulfonic acid and/or carboxylate and/or sulfonate groups on the colorant. Specific examples of suitable acids include organic sulfonic acids, including alkyl benzene sulfonic acids such as para-toluene-sulfonic acid, dodecylbenzenesulfonic acid, and the like, p-toluene sulfonic acid, hydrochloric acid, trifluoroacetic acid, methylsulfonic acid, trifluoromethyl sulfonic acid, hydrobromic acid, and the like, as well as mixtures thereof. The acid is present in any desired or effective amount, in one embodiment at least about 2 percent by weight of the amount of colorant according to the present disclosure, and in another embodiment at least about 5 percent by weight of the amount of colorant according to the present disclosure, and in one embodiment no more than about 100 percent by weight of the amount of the colorant according to the present disclosure, and in another embodiment no more than about 30 percent by weight of the colorant according to the present disclosure, although the amount of acid can be outside of these ranges.

The inks of the present disclosure can also optionally contain an antioxidant. The optional antioxidants of the ink compositions protect the images from oxidation and also protect the ink components from oxidation during the heating portion of the ink preparation process. Specific examples of suitable antioxidants include NAUGUARD® 524, NAUGUARD® 76, and NAUGUARD® 512 (commercially available from Uniroyal Chemical Company, Oxford, Conn.), IRGANOX® 1010 (commercially available from Ciba Geigy), and the like. When present, the optional antioxidant is present in the ink in any desired or effective amount, in one embodiment of at least about 0.01 percent by weight of the ink, in another embodiment of at least about 0.1 percent by weight of the ink, and in yet another embodiment of at least about 1 percent by weight of the ink, and in one embodiment of no more than about 20 percent by weight of the ink, in another embodiment of no more than about 5 percent by weight of the ink, and in yet another embodiment of no more than about 3 percent by weight of the ink, although the amount can be outside of these ranges.

The inks of the present disclosure can also optionally contain a viscosity modifier. Examples of suitable viscosity modifiers include aliphatic ketones, such as stearone, and the like. When present, the optional viscosity modifier is present in the ink in any desired or effective amount, in one embodiment of at least about 0.1 percent by weight of the ink, in another embodiment of at least about 1 percent by weight of the ink, and in yet another embodiment of at least about 10 percent by weight of the ink, and in one embodiment of no more than about 99 percent by weight of the ink, in another embodiment of no more than about 30 percent by weight of the ink, and in yet another embodiment of no more than about 15 percent by weight of the ink, although the amount can be outside of these ranges.

Other optional additives to the inks include clarifiers, such as UNION CAMPS® X37-523-235 (commercially available from Union Camp), in an amount in one embodiment of at least about 0.01 percent by weight of the ink, in another embodiment of at least about 0.1 percent by weight of the ink, and in yet another embodiment of at least about 5 percent by weight of the ink, and in one embodiment of no more than about 98 percent by weight of the ink, in another embodiment of no more than about 50 percent by weight of the ink, and in yet another embodiment of no more than about 10 percent by weight of the ink, although the amount can be outside of these ranges, tackifiers, such as FORAL® 85, a glycerol ester of hydrogenated abietic (rosin) acid (commercially available from Hercules), FORAL® 105, a pentaerythritol ester of hydroabietic (rosin) acid (commercially available from Hercules), CELLOLYN® 21, a hydroabietic (rosin) alcohol ester of phthalic acid (commercially available from Hercules), ARAKAWA KE-311 Resin, a triglyceride of hydrogenated abietic (rosin) acid (commercially available from Arakawa Chemical Industries, Ltd.), synthetic polyterpene resins such as NEVTAC® 2300, NEVTAC® 100, and NEVTAC® 80 (commercially available from Neville Chemical Company), WINGTACK® 86, a modified synthetic polyterpene resin (commercially available from Goodyear), and the like, in an amount in one embodiment of at least about 0.1 percent by weight of the ink, in another embodiment of at least about 5 percent by weight of the ink, and in yet another embodiment of at least about 10 percent by weight of the ink, and in one embodiment of no more than about 98 percent by weight of the ink, in another embodiment of no more than about 75 percent by weight of the ink, and in yet another embodiment of no more than about 50 percent by weight of the ink, although the amount can be outside of these range, adhesives, such as VERSAMID® 757, 759, or 744 (commercially available from Henkel), in an amount in one embodiment of at least about 0.1 percent by weight of the ink, in another embodiment of at least about 1 percent by weight of the ink, and in yet another embodiment of at least about 5 percent by weight of the ink, and in one embodiment of no more than about 98 percent by weight of the ink, in another embodiment of no more than about 50 percent by weight of the ink, and in yet another embodiment of no more than about 10 percent by weight of the ink, although the amount can be outside of these ranges, plasticizers, such as UNIPLEX® 250 (commercially available from Uniplex), the phthalate ester plasticizers commercially available from Monsanto under the trade name SANTICIZER®, such as dioctyl phthalate, diundecyl phthalate, alkylbenzyl phthalate (SANTICIZER® 278), triphenyl phosphate (commercially available from Monsanto), KP-140®, a tributoxyethyl phosphate (commercially available from FMC Corporation), MORFLEX® 150, a dicyclohexyl phthalate (commercially available from Morflex Chemical Company Inc.), trioctyl trimellitate (commercially available from Eastman Kodak Co.), and the like, in an amount in one embodiment of at least about 0.1 percent by weight of the ink, in another embodiment of at least about 1 percent by weight of the ink, and in yet another embodiment of at least about 2 percent by weight of the ink, and in one embodiment of no more than about 50 percent by weight of the ink, in another embodiment of no more than about 30 percent by weight of the ink, and in yet another embodiment of no more than about 10 percent by weight of the ink, although the amount can be outside of these ranges, and the like.

The ink compositions of the present disclosure in one embodiment have melting points of no lower than about 50° C., in another embodiment of no lower than about 70° C., and in yet another embodiment of no lower than about 80° C., and have melting points in one embodiment of no higher than about 160° C., in another embodiment of no higher than about 140° C., and in yet another embodiment of no higher than about 100° C., although the melting point can be outside of these ranges.

The ink compositions of the present disclosure generally have melt viscosities at the jetting temperature (in one embodiment no lower than about 75° C., in another embodiment no lower than about 100° C., and in yet another embodiment no lower than about 120° C., and in one embodiment no higher than about 180° C., and in another embodiment no higher than about 150° C., although the jetting temperature can be outside of these ranges) in one embodiment of no more than about 30 centipoise, in another embodiment of no more than about 20 centipoise, and in yet another embodiment of no more than about 15 centipoise, and in one embodiment of no less than about 2 centipoise, in another embodiment of no less than about 5 centipoise, and in yet another embodiment of no less than about 7 centipoise, although the melt viscosity can be outside of these ranges.

The ink compositions of the present disclosure can be prepared by any desired or suitable method. For example, the ink ingredients can be mixed together, followed by heating, to a temperature in one embodiment of at least about 100° C., and in one embodiment of no more than about 140° C., although the temperature can be outside of these ranges, and stirring until a homogeneous ink composition is obtained, followed by cooling the ink to ambient temperature (typically from about 20 to about 25° C.). The inks of the present disclosure are solid at ambient temperature. In a specific embodiment, during the formation process, the inks in their molten state are poured into molds and then allowed to cool and solidify to form ink sticks.

The inks of the present disclosure can be employed in apparatus for direct printing ink jet processes and in indirect (offset) printing ink jet applications. Another embodiment of the present disclosure is directed to a process which comprises incorporating an ink of the present disclosure into an ink jet printing apparatus, melting the ink, and causing droplets of the melted ink to be ejected in an imagewise pattern onto a recording substrate. A direct printing process is also disclosed in, for example, U.S. Pat. No. 5,195,430, the disclosure of which is totally incorporated herein by reference. Yet another embodiment of the present disclosure is directed to a process which comprises incorporating an ink of the present disclosure into an ink jet printing apparatus, melting the ink, causing droplets of the melted ink to be ejected in an imagewise pattern onto an intermediate transfer member, and transferring the ink in the imagewise pattern from the intermediate transfer member to a final recording substrate. In a specific embodiment, the intermediate transfer member is heated to a temperature above that of the final recording sheet and below that of the melted ink in the printing apparatus. An offset or indirect printing process is also disclosed in, for example, U.S. Pat. No. 5,389,958, the disclosure of which is totally incorporated herein by reference. In one specific embodiment, the printing apparatus employs a piezoelectric printing process wherein droplets of the ink are caused to be ejected in imagewise pattern by oscillations of piezoelectric vibrating elements. Inks of the present disclosure can also be employed in other hot melt printing processes, such as hot melt acoustic ink jet printing, hot melt thermal ink jet printing, hot melt continuous stream or deflection ink jet printing, and the like. Phase change inks of the present disclosure can also be used in printing processes other than hot melt ink jet printing processes.

Any suitable substrate or recording sheet can be employed, including plain papers such as XEROX® 4024 papers, XEROX® Image Series papers, Courtland 4024 DP paper, ruled notebook paper, bond paper, silica coated papers such as Sharp Company silica coated paper, JuJo paper, HAMMERMILL LASERPRINT® paper, and the like, transparency materials, fabrics, textile products, plastics, polymeric films, inorganic substrates such as metals and wood, and the like.

EXAMPLES

The following Examples are being submitted to further define various species of the present disclosure. These Examples are intended to be illustrative only and are not intended to limit the scope of the present disclosure. Also, parts and percentages are by weight unless otherwise indicated.

Example 1 Part A: Synthesis of the Leuco Version of the Dye

About 30.8 grams of 2,6-diethyl aniline of the formula

17.5 grams of 2,6-dichloro benzaldehyde of the formula

and 50 grams of deionized water were added to a 150 milliliter 1-neck round bottom flask equipped with a Teflon® coated magnet, condenser, and oil bath. The contents were mixed and 21.6 grams of concentrated H₂SO₄ were added to the mixed contents. The flask was placed in a 100° C. oil bath and allowed to stir and heat. After about 24 hours of heating, the crude product was poured into a 1 liter beaker containing 500 milliliters of ice water, stirred for about 30 minutes, and allowed to set overnight. The product mixture was then neutralized with about 30 milliliters of 40% NaOH and collected via vacuum filtration. The tan solid was washed with about 500 milliliters of water, reslurried in about 500 milliliters of water, and this process of washing and reslurrying was repeated. The filtered solids were then allowed to dry. The Leuco (colorless) version of the basic dye produced is believed to be of the formula

Example 1 Part B: Oxidation of the Leuco Version of the Basic Dye

The solid collected in Example 1, Part A, was added to a 500 milliliter 1-neck round bottom flask equipped with a Teflon® coated magnet, condenser and oil bath. 250 milliliters of ethyl alcohol and 25 grams of chloranil (an oxidizing agent) were added and the flask was placed in a 70 C oil bath with stirring. A blue color began to develop immediately and deepen with time. The flaks was heated fro about 2 hours to insure complete oxidation of the Leuco form of the dye to the fully developed form, believed to be of the formula

Example 1 Part C: Formation of the Carbinol Form of the Basic Dye

After the reaction mixture had been fully oxidized, as outlined in Example 1, Part B, about 25 milliliters of 40% NaOH was added t the heated/stirred blue dye. The blue color immediately disappeared indicating the formation of the carbinol form of the dye. Heating and stirring was continued for about 5 additional minutes. The crude product was poured into a 1000 milliliter beaker containing 250 milliliters of water and 5 grams of 40% NaOH and allowed to set overnight. The carbinol form of the dye is believed to be of the formula

Example 1 Part D: Formation of the Carboxylic Acid Containing Methine Yellow Dye

50 grams of ethoxylated p-formyl aniline (see U.S. Pat. No. 4,658,064, the disclosure of which is hereby incorporated by reference herein in its entirety) of the formula

was added to a 250 milliliter 1-neck round bottom flask equipped with a condenser having a Teflon coated magnet and an oil bath, along with 7.6 grams of cyanoacetic acid of the formula

a spatula tip of ammonium acetate (as a catalyst), and 200 milliliters of ethanol. The reaction mixture was refluxed for about 4 hours and the ethanol removed by distillation leaving a viscous yellow liquid methane dye believe to be of the formula

Example 1 Part E: Formation of the Green Basic Dye/Acid Dye Internal Salt

About 30 grams of the carboxylated methane yellow dye from Example 1, Part D about 29 grams of the carbinol form of the tetraethyl version of BB&& dye from example 1, part C, and about 300 milliliters of ethanol were added to a 500 milliliter beaker equipped with a Teflon® coated magnet, condenser and oil bath. The mixture was stirred and heated in a 100° C. oil bath until all of the ethanol boiled off, at which time about 300 milliliters of additional ethanol was added and allowed to boil off. This process was repeated 2 additional times in order to insure that the water formed by the carbinol/acid interaction was removed leaving the Basic Dye/Acid Dye Internal Salt. The final product when cooled was a Green waxy dye believed to be of the formula

Example 2 Part A: Synthesis of the Leuco Version of the Basic Dye

About 29.8 grams of N,N-diethylamino aniline of the formulae

about 17.7 grams of 4-diethylamino benzaldehyde of the formula

and 100 grams of deionized water were added to a 150 milliliter 1-neck round bottom flask equipped with a Teflon® coated magnet, condenser, and oil bath. The contents were mixed and 21.6 grams of concentrated H₂SO₄ were added. The flask was placed in a 100° C. oil bath and allowed to stir and heat. After about 24 hours of heating, the crude product was poured into a 1 liter beaker containing 500 milliliters of ice water and stirred for about 30 minutes and allowed to set overnight. The product mixture was then neutralized with 40% NaOH (about 30 milliliters) and collected via vacuum filtration. The tan solid was washed with about 500 milliliters of water, reslurried in about 500 milliliters of water, filtered, and this processed was repeated. The filtered solids were then allowed to dry. The Leuco (colorless) version of the basic dye produced is believed to be of the formula

Example 2 Part B: Oxidation of the Leuco Version of the Basic Dye

The solid collected in Example 2, Part A, 150 milliliters of ethyl alcohol, and 25 grams of chloranil (an oxidizing agent) were added to a 150 milliliter 1-neck round bottom flask equipped with a Teflon® coated magnet, condenser, and oil bath. The flask was placed in a 70° C. oil bath with stirring. A blue color began to develop immediately and deepen with time. The flask was heated for about 2 hours to insure complete oxidation of the Leuco form of the dye to the fully developed form, believed to be of the formula

Example 2 Part C: Formation of the Carbinol Form of the Basic Dye

After the reaction mixture had been fully oxidized, as outlined in Example 2, Part B, the pH was made alkaline with 40% NaOH. The blue color immediately disappeared indicating the formation of the carbinol form of the dye. Heating and stirring was continued for 5 additional minutes. The crude product was poured into a 1000 milliliter beaker containing 150 milliliters of water and 2.5 grams of 40% NaOH and allowed to set overnight. The solids were collected by filtration and placed in a sealed container (approx 22.4 grams of carbinol violet dye obtained). The carbinol form of the dye is believed to be of the formula

Example 2 Part D: Stearyl Urethane Derivitization of the Mono-Hydroxyl Formyl Aniline

40 grams of mono-hydroxylalkoxylated p-formyl aniline (see U.S. Pat. No. 7,034,185, the disclosure of which is hereby incorporated by reference herein in its entirety) of the formula

21.4 grams of stearylisocynate of the form CH₃—(CH₂)₁₇—NCO

and 2 drops of dibutyltindilaurate catalyst were added to a 250 milliliter beaker equipped with a Teflon coated magnet and a 120° C. oil bath and heated with stirring until infrared spectroscopy reading indicated that the reaction was complete. The contents were then cooled and allowed to solidify into a soft pate-wax consistency. The produced stearyl urethane derivatized p-formylaniline alkoxylate is believed to be of the formula

Example 2 Part E: Formation of the Carboxylic Acid Containing Methine Yellow Dye

7.0 grams of cyanoacetic acid and about 80 milliliters of ethanol were added to the 250 milliliter beaker containing the stearyl urethane derivatized p-formylaniline alkoxylate from Example 2, Part D, and the beaker was placed in a 100° C. oil bath with watch glass. The contents were heated and stirred for about 3 to about 4 hours maintaining the level of ethanol throughout the entire reaction by adding more when necessary. After 4 hours, the reaction was poured into a 1 liter beaker containing 500 milliliters of deionized water and allowed to stir overnight. The next day the product had formed a paste wax-like consistency and the water-ethanol solution was decanted. 500 milliliters of water were added, heated with stirring in a 100° C. oil bath for 1 hour, cooled, and the water decanted. The stearyl urethane derivatized alkoxylate carboxylated methane yellow dye obtained is believed to be of the formula

Example 2 Part F: Formation of the Basic Dye/Acid Dye Internal Salt

22.4 grams of the carbinol form of the violet dye from Example 2, Part C and about 300 milliliters of ethanol were added to the stearyl urethane derivatized alkoxylate carboxylated methane yellow dye from Example 2, Part D in a 250 milliliter beaker equipped with a Teflon® coated magnet. The mixture was stirred and heated in a 100° C. oil bath until all of the ethanol boiled off, at which time 300 milliliters additional ethanol was added and allowed to boil off. This was repeated 2 additional times in order to insure the water formed by the carbinol/acid interaction was removed leaving the Basic Dye/Acid Dye Internal Salt believed to be of the formula

The final product when cooled was a waxy dye having a bluish grey color.

Example 3 Part A. Preparation of Monohydroxyl Triphenylmethane Polyoxyalkylene Triphenyl Methane Violet Colorant

To a 100 milliliter 1-necked round bottom flask equipped with a magnetic stirrer was added 20.0 grams (about 0.029 moles) of the para-formylated POE(3.5) POP(6.5) N-ethyl aniline adduct prepared in Example II of U.S. Pat. No. 7,094,812, the disclosure of which is totally incorporated by reference herein, 8.85 grams of N,N-diethylaniline (obtained from Aldrich Chemical Co.), 0.6 grams of urea (obtained from Aldrich Chemical Co.), and 1.5 grams of concentrated H₂SO₄ (obtained from Aldrich Chemical Co.). The flask was placed into a 100° C. oil bath, stirring was commenced, and the mixture was allowed to heat/stir for 3 hours. After 3 hours, 3.1 grams of benzoquinone (obtained from Aldrich Chemical Co.) and 2.0 grams of water were added to the reaction mixture and stirring/heating was continued for 2 hours, at which time the flask was removed from the heat and the violet liquid product was allowed to cool to room temperature. The product at this point was a viscous violet liquid consistent with the formula

Example 3 Part B: Stearyl Urethane Derivitization of the Mono-Hydroxyl Triphenyl methane

10 grams of pure mono-hydroxylalkoxylated from Example 3, Part A, (which is purified dissolving in 100 grams of dichloromethane, placed in a separatory funnel, washed twice with 50 grams of deionized water, followed by distillation of the dichloromethane leaving the desired product) 2.8 grants of stearyl isocyanate of the formula CH₃—(CH₂)₁₇—NCO

and 1 drop of dibutyltindilaurate catalyst is added to a 100 milliliter beaker equipped with a Teflon coated magnet and a 120° C. oil bath and heated with stirring until infrared spectroscopy reading indicates that the reaction is complete. The contents are then cooled and allowed to solidify into a soft pate-wax consistency. The produced stearyl urethane derivatized triphenyl methane is believed to be of the formula

Example 3 Part C: Formation of the Carbinol Form of the Basic Dye

To the 250 milliliter beaker equipped with a Teflon® coated magnet containing the urethane triphenylmethane of Example 3, Part B, is added 50 milliliters of ethyl alcohol and stirred until the product dissolves. The pH is made alkaline with 40% NaOH. The violet color immediately disappears indicating the formation of the carbinol form of the dye. Heating and stirring is continued for 5 additional minutes. The crude product is poured into a 1000 milliliter beaker containing 150 milliliters of water and 2.5 grams of 40% NaOH and allowed to set overnight. The solids are collected by filtration and placed in a sealed container. The carbinol form of the dye is believed to be of the formula

Example 3 Part D: Formation of the Basic Dye/Acid Dye Internal Salt

1.26 grams of the free acid of Acid Orange 8 and about 50 milliliters of ethanol is added to 5.0 grams of the stearyl urethane derivatized triphenylmethane violet dye from Example 2, Part C in a 150 milliliter beaker equipped with a Teflon® coated magnet. The mixture is stirred and heated in a 100° C. oil bath until all of the ethanol boils off; at which time about 50 milliliters additional ethanol is added and allowed to boil off. This is repeated 2 additional times in order to insure the water formed by the carbinol/acid interaction is removed leaving the Basic Dye/Acid Dye Internal Salt believed to be of the formula

Example 3 Part E: Formation of the Basic Dye/Acid Dye Internal Salt

About 1.73 grams of the free acid of Acid Orange 74 and about 50 milliliters of ethanol is added to about 5.0 grams of the stearyl urethane derivatized triphenylmethane violet dye from Example 2, Part C in a 150 milliliter beaker equipped with a Teflon® coated magnet. The mixture is stirred and heated in a 100° C. oil bath until all of the ethanol boils off, at which time about 50 milliliters additional ethanol is added and allowed to boil off. This is repeated 2 additional times in order to insure the water formed by the carbinol/acid interaction is removed leaving the Basic Dye/Acid Dye believed to be of the formula

Example 4 Preparation of an Ink Base

An ink base was prepared by melting, admixing, and filtering the following ingredients:

43.59 parts by weight polyethylene wax (PE 655®, obtained from Baker Petrolite) of the formula CH₃(CH₂)₅₀CH₃);

19.08 parts by weight stearyl stearamide wax (KEMAMIDE® S-180, obtained from Crompton Corporation);

18.94 parts by weight tetra-amide resin obtained from the reaction of one equivalent of a C-36 dimer acid (obtained from Uniqema, New Castle, Del.) with two equivalents of ethylene diamine and UNICID® 700 (obtained from Baker Petrolite), a long chain hydrocarbon having a terminal carboxylic acid group, prepared as described in Example 1 of U.S. Pat. No. 6,174,937, which is hereby incorporated by reference herein in its entirety;

11.71 parts by weight urethane resin obtained from the reaction of two equivalents of ABITOL® E hydroabietyl alcohol (obtained from Hercules Inc.) and one equivalent of isophorone diisocyanate, prepared as described in Example 1 of U.S. Pat. No. 5,782,966, which is hereby incorporated by reference herein;

6.48 parts by weight urethane resin that is the adduct of three equivalents of stearyl isocyanate and a glycerol-based alcohol, prepared as described in Example 4 of U.S. Pat. No. 6,309,453, which is hereby incorporated by reference herein in its entirety;

0.20 parts by weight NAUGUARD® 445 antioxidant (obtained from Uniroyal Chemical Co.).

Thereafter, 600 grams of the ink carrier components as listed above in the percentages as listed above were added to a 1 liter beaker and heated in an oven at 135° C. until molten. Subsequently, the beaker was inserted into a heating mantle set to 135° C. and the contents of the beaker were stirred for 45 minutes. The resulting ink was then filtered through a combination of Whatrnan #3 and 0.2 micron NAE filters and placed in a Mott filter assembly. Filtration was supported by the addition of 1 percent by weight FILTER-AID obtained from Fluka Chemika, Switzerland, and proceeded at a temperature of 135° C. until complete after 6 hours. The ink base was poured into molds containing about 31 grams of the colorless ink base and allowed to cool.

Example 5 Preparation of Ink Containing Colorant

About 30.0 grams of ink base from Example 4 was placed in a 100 milliliter beaker with a magnetic stir bar and subsequently placed in a 135° C. oil bath until molten. About 2.0 grams of the dye product of Example 1, Part E was then added and stirred for about 3 hours. The magenta colorant was then poured into an aluminum mold.

Example 6 Preparation of Ink Containing Colorant

About 30.0 grams of ink base from Example 3 was placed in a 100 milliliter beaker with a magnetic stir bar and subsequently placed in a 135 C oil bath until molten. About 2.0 grams of the dye product of Example 2, Part F was then added and stirred for about 3 hours. The magenta colorant was then poured into an aluminum mold.

Example 7 Printing of Ink Samples Containing Colorant

Printed samples of the inks prepared in Examples 4 and 5 were generated on HAMMERMILL LASERPRINT® paper using a K Printing Proofer (manufactured by RK Print Coat Instrument Ltd., Litlington, Royston, Heris, SG8 0OZ, U.K.). In this method, the tested inks were melted onto a printing plate set at 150° C. A roller bar fitted with the paper was then rolled over the plate containing the melted ink on its surface. The ink on the paper was cooled, resulting in three separated images of rectangular blocks (three different intensities of ink coverage on the paper). The most intensely colored block contained the most ink deposited on the paper, and was therefore used to obtain the color value measurements. The printed samples were evaluated visually.

It will be appreciated that various of the above-disclosed and other features and functions, or alternatives thereof, may be desirably combined into many other different systems or applications. Also that various presently unforeseen or unanticipated alternatives, modifications, variations or improvements therein may be subsequently made by those skilled in the art which are also intended to be encompassed by the following claims. Unless specifically recited in a claim, steps or components of claims should not be implied or imported from the specification or any other claims as to any particular order, number, position, size, shape, angle, color, or material. 

1. A phase change ink composition comprising a phase change ink carrier and a colorant composition having a basic dye component and an acid dye component providing an internal salt composition; wherein the basic dye component comprises a compound of the formula;

and wherein the acid dye component comprises a compound of the formula

providing a basic dye-acid dye internal salt composition.
 2. A phase change ink composition according to claim 1, wherein the phase change ink carrier comprises a monoamide, a tetra-amide, or a mixture thereof.
 3. A phase change ink composition according to claim 1, wherein the phase change ink carrier comprises (a) stearyl stearamide, (b) a dimer acid based tetra-amide that is the reaction product of dimer acid, ethylene diamine, and stearic acid, or (c) mixtures thereof.
 4. A phase change ink composition according to claim 1, wherein the phase change ink carrier comprises an isocyanate-derived material, a urethane isocyanate-derived material, a urea isocyanate-derived material, a urethane/urea isocyanate-derived material, or mixtures thereof.
 5. A phase change ink composition according to claim 1, wherein the phase change ink carrier comprises a mixture of one or more amides and one or more isocyanate-derived materials.
 6. A phase change ink composition according to claim 1, wherein the phase change ink carrier comprises one or more materials selected from paraffins, microcrystalline waxes, polyethylene waxes, ester waxes, amide waxes, fatty acids, fatty alcohols, fatty amides, sulfonamide materials, tall oil rosins, rosin esters, ethylene/vinyl acetate copolymers, ethylene/acrylic acid copolymers, ethylene/vinyl acetate/acrylic acid copolymers, copolymers of acrylic acid with polyamides, ionomers, and mixtures thereof.
 7. A phase change ink composition according to claim 1, wherein the phase change ink carrier is present in the ink in an amount of at least about 0.1 percent by weight of the ink and wherein the phase change ink carrier is present in the ink in an amount of no more than about 99 percent by weight of the ink.
 8. A phase change ink composition according to claim 1, wherein the ink further contains an antioxidant.
 9. A phase change ink composition according to claim 8, wherein the antioxidant is present in the ink in an amount of at least about 0.01 percent by weight of the ink, and wherein the antioxidant is present in the ink in an amount of no more than about 20 percent by weight of the ink.
 10. A phase change ink composition according to claim 1, wherein the ink further contains a viscosity modifier.
 11. A phase change ink composition according to claim 10, wherein the viscosity modifier is present in the ink in an amount of at least about 0.1 percent by weight of the ink and wherein the viscosity modifier is present in the ink in an amount of no more than about 99 percent by weight of the ink.
 12. A phase change ink composition according to claim 1, wherein the colorant is present in the ink in an amount of at least about 0.1 percent by weight of the ink.
 13. A phase change ink composition according to claim 1, wherein the colorant is present in the ink in an amount of no more than about 20 percent by weight of the ink.
 14. A phase change ink composition according to claim 1, wherein the ink has a melting point of no lower than about 50° C. and wherein the ink has a melting point of no higher than about 160° C.
 15. A phase change ink composition according to claim 1, wherein the ink has a melt viscosity at a temperature of about 140° C. of no more than about 30 centipoise.
 16. A phase change ink composition according to claim 1, wherein the ink has a melt viscosity at a temperature of about 140° C. of no less than about 1 centipoise.
 17. A process employing the ink of claim 1 which comprises (1) incorporating into an ink jet printing apparatus the phase change ink composition according to claim 1; (2) melting the ink; and (3) causing droplets of the melted ink to be ejected in an imagewise pattern onto a substrate.
 18. A process according to claim 17, wherein the printing apparatus employs a piezoelectric printing process wherein droplets of the ink are caused to be ejected in imagewise pattern by oscillations of piezoelectric vibrating elements.
 19. A process according to claim 17, wherein the substrate is a final recording sheet and droplets of the melted ink are ejected in an imagewise pattern directly onto the final recording sheet.
 20. A process according to claim 17, wherein the substrate is an intermediate transfer member and droplets of the melted ink are ejected in an imagewise pattern onto the intermediate transfer member followed by transfer of the imagewise pattern from the intermediate transfer member to a final recording sheet.
 21. A process according to claim 20, wherein the intermediate transfer member is heated to a temperature above that of the final recording sheet and below that of the melted ink in the printing apparatus. 